Scanning device including an objective lens formed of two...

Details Scanning device including an objective lens formed of two... Scanning device including an objective lens formed of two...

2006-12-12

2006-12-12

Spector, David N. (Department: 2873)

Optical: systems and elements

Lens

Including a nonspherical surface

C359S708000, C359S718000, C369S112230

Reexamination Certificate

active

07149040

ABSTRACT:
An optical scanning device (1) for scanning an information layer (4) of an optical record carrier (2), the information layer (4) being covered by a transparent layer (3) of thickness tdand refractive index nd. The device comprises a radiation source (11) for generating a radiation beam (12, 15, 20) and an objective system (18) for converging the radiation beam on the information layer. The objective system is characterised in comprising a lens comprising a synthetic resin on a substrate, the total thickness t of the lens satisfying the condition: Formula (I), where FWD+td
d<0.51, and FWD is the free working distance between the lens (18) and carrier (2) and Φ is the entrance pupil diameter of the lens (18), where t, td, Φ and FWD are expressed in millimeters.

REFERENCES:
patent: 4319945 (1982-03-01), Howden
patent: 4623496 (1986-11-01), Verhoeven et al.
patent: 6038077 (2000-03-01), Braat
patent: 6665132 (2003-12-01), Hendriks et al.
patent: 6995929 (2006-02-01), Hendriks
patent: 7009744 (2006-03-01), Hendriks et al.
patent: 7034974 (2006-04-01), Hendriks et al.
patent: 7050246 (2006-05-01), Hendriks
M. Itonga et al; “Single Objective Lens Having Numerical Aperture 0.85 for a High Density Ooptical Disk System”, Japan J. Appl. Phys. vol. 41, 2002, pp. 1798-1803, Part 1, No. 3B.

Affiliated with

Also associated with

Rating

Scanning device including an objective lens formed of two... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Scanning device including an objective lens formed of two..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Scanning device including an objective lens formed of two... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3706094